Interfacial anti-fatigue effect in graphene-copper nanolayered composites under cyclic shear loading.

Low-cycle fatigue behaviors of graphene-copper nanolayered (GCuNL) composites are explored at different interface configurations and repeat layer spacings. The graphene interfaces can trap dislocations through impeding the propagation of dislocations in copper layers, giving rise to the absence of softening, and an increase in the fatigue strength of GCuNL composites (up to 400% that of pure copper). This anti-fatigue effect is independent of the crystal orientation of copper or the chirality of graphene due to interfacial constraints and can be controlled by tailoring the repeat layer spacing. Low repeat layer spacing increases the instability and nonlinearity of the composites, while high repeat layer spacing decreases the anti-fatigue effect. The optimum value of the repeat layer spacing for the GCuNL composites is 3-7 nm, in order to achieve a balanced anti-fatigue capability and interface stability.